var path = AURI+'resource/image/';
var rOver = new Array;
var r = new Array;

r[0] = new Image();
r[1] = new Image();
r[2] = new Image();
r[3] = new Image();

rOver[0] = new Image(); 
rOver[1] = new Image();
rOver[2] = new Image();
rOver[3] = new Image();

r[0].src = path+'nav_overview.png';
r[1].src = path+'nav_news.png';
r[2].src = path+'nav_about.png';
r[3].src = path+'nav_feedback.png';

rOver[0].src = path+'nav_overview_h.png';
rOver[1].src = path+'nav_news_h.png';
rOver[2].src = path+'nav_about_h.png';
rOver[3].src = path+'nav_feedback_h.png';

var handleRollOvers = function( key, imgid  ) {
        if($(imgid)) {
            /* mouseover */
            $(imgid).addEvent('mouseover', function() {
                $(imgid).setProperty('src', rOver[key].src);
                enableAlphaImage($(imgid));
            });
    		/* mouseout */
        	$(imgid).addEvent('mouseout', function() {
            	$(imgid).setProperty('src', r[key].src);
                enableAlphaImage($(imgid));
    		});
        	/* set style */
            if(window.ie) {
                $(imgid).setStyle('cursor','hand');
    		} else {
        		$(imgid).setStyle('cursor','pointer');
            }
        }
}

window.addEvent("domready", function() {
    handleRollOvers(0, 'nav_home');
});
window.addEvent("domready", function() {
    handleRollOvers(1, 'nav_news');
});
window.addEvent("domready", function() {
    handleRollOvers(2, 'nav_about');
});
window.addEvent("domready", function() {
    handleRollOvers(3, 'nav_feedback');
});